Centrifugal separator



Oct. 21, 1941. J. J. SERRELL, JR V 2,259,665

' CENTRIFUGAL SEPARATOR File d Feb. 10, 1959 l N VEN TOR:

John J. Serrell It B W1 M A TTORNEY Patented Oct. 21, 1941 UNMED SKATES PATEN'E' CENTRXFUGAL SEIPARA'EQR John .17. geill'ell, .lr., Elizabeth, N. Lfiassignor to The Sharples Corporation, Philade phia, ya, a corporation of Delaware Appiication February it, 1939, Serial No; 255,588

The present invention pertains to centrifugal separators. Features of the invention are applicable, to centrifugal separators adapted to discharge bontinuously two or more liquid effluents (separator type), or to centrifugal soparators which retain in the rotor a constituent removed from the liquid fed to the rotor (clarifier type), or to centrifugal separators which simultaneously perform both of these functions. The centrifugal separator of the invention includes many features in common with the centrifugal of; the patent to Ayres, 2,138,468, and may be regarded as an improvement in the sep arator of that patent. The separator of the present invention, like that of the Ayres patent, is useful in the performance of industrial operations such as concentration of emulsions, the

separation of immiscible liquids from each other, or the simultaneous separation of solid impurities from a mixture of liquids or a emulsion, while effecting separating or concen rating 'operations upon such mixture or emulsion.

The machine of Ayres Patent 2,138,468 has proved particularly useful in the commercial concentration of emulsions such as rubber latex. In the concentration of latex, it is important that the concentrating operation be carried. on in such a manner as to minimize coagulation of.

latex particles. Such coagulation, when it occurs, has the dual disadvantage of converting the productto an undesirable condition and causing cloggage of the machine, with the resultant necessity for discontinuing the concentrating operation to clean the machine.

The introduction of the machine of Ayres Patent 2,138,468 into use for latex concentration has represented an important advance in that industry, enabling the operator to accomplish the concentrating operation in an effective man-- the body of latex in this accelerating zone to prevent substantial deposition of solids or concentration of latex this section of the rotor. The latex is thus brought up to the desired which serves solely as an accelerating and feeding means for the main body of the rotor, and the function of concentrating the latex is accomplished in the subsidence section of the rotor 5 to which the latex is passed from this preliminary accelerating and feeding section.

While, as stated above, the machine of the Ayres patent has represented an important advance in the art of centrifugal latex concentra-' tion. certain 'difilculties have been encountered in theme of that machine, and these difi culties are directly connected with the features by c which the advantageous results of gentle accel 1 eration of the latex are obtained. 'In theuse of the machine of the Ayres patent, the principle of indirect acceleration of the main body of latex bycontact with a thin layer of latex which is positively accelerated results in minimizing coagulation as desired, but at the same time, the

part of the body of the latex being subjected to indirectacceleratlon which is more remote from the positive accelerating fins 28 of the Ayres patent is necessarily more slowly accelerated than the part of that body directly subjected to 2 the accelerating action of those fins and the part "closer to the part subjected to. such-direct acceleration. As a consequence of this fact, the part of the body of the latex which is imperfectly accelerated tends 'to pass from the acceleratorzone downwardly from the rotor through the opening 29.

1In any centrifugal machine for concentrating .latex, .a certain degree of coagulation of the latex inevitably occurs. While this is mini mized in the Ayres machine, latex coagulum gradually accumulates in the space between the,

acceleratorflns 28 in the use of that machine, and this accumulation of latex in the positive acceleration zone reduces the efliciency of acceleration and increases the tendency; discussed above, of part of the body of latex to pass downwardly from the rotor through the opening 29. The principal object of the present invention has been to ameliorate the difficulties discussed o above. Further objects of the invention and the manner in which they have been attained will be evident fromv a readi ng of the following speciflcation in the light of the attached drawing, in

which,

Fig. 1 is a central longitudinal section through the centrifugal rotor of the. presentinvention (this cross section is taken on the line l-l of Fig. 3).

Fig. 2 is a cross section on the line 22 of speed in thispreliminary section oftherotor, Fig. 1.

Fig. 3 is a cross section on the line 3-3 of Fi 1.

In the following detailed description, the features of the machine of the present invention will .be described with reference to the concentration of rubber latex to produce and separateiy discharge eflluents relatively rich and relatively poor in dispersed rubber particles, as light and heavy confiuents respectively. It will be understood that this mode of description is chosen merely for the purpose of convenience, and that the machine of the invention may be applied to many centrifugal problems other than the concentration of rubber latex.

Referring to the drawing by reference characters, the latex emulsion is fed to the centrifugal separator through a conduit Ill and injected 'into the centrifugal rotor of the invention through a nozzle H. In the embodiment of the invention illustrated in the drawing, the rotor is mounted to revolve on a vertical axis, and the feed of latex is directed upwardly into this rotor. The invention is not limited to such an arrangement, however, as features of the invention could be used in connection with rotors mounted to revolve about other axes or in connection with rotors in which the direction of feed of the influent fluid is not upward.

In the preferred form of the invention, as illustrated, the latex is directed upwardly from the nozzle ll into impingement against a deflector-or spreader member 32, which may be of conical shape, as illustrated. This deflector or spreader member deflects the incoming stream into contact with primary accelerating means for bringing the latex up to the-speed of the rotor.-

In the preferred embodimen twof the invention, the primary accelerator means comprises a transversely extending plate I! provided with a plurality of accelerator members or fins l6. As illustrated inthe'drawing,,these fins extend in a radial direction, but it is not necessary that they be arranged strictly radially, as those familiar with the design of accelerators for use in centrifugal separators will ap reciate.

The conical spreader 32, accelerator plate i5 and accelerator. members or fins It may be mounted in an accelerator cage I3, as illustrated. In case these members form a part of a cagelike structure, as suggested. openings II are preferably provided in the upper end of the cage and in the circumferential wall of the cage to afford provision-for the passage of latex adequately accelerated by the members or fins 16,

from the cage outwardly toward the rotor wall.

A central opening I8 is providedin the plate l5,

tapermit passage of the latex jetted into the rotor into impingement against the deflector or spreader member 32, and latex inadequately ac- 'celerated by the members or fins it, because of the factors discussed above in connection with the machine of Ayres Patent2,138,468, may pass through this central opening (downwardly, in-the embodiment illustrated) into contactwith a second (and in this embodiment,underlying) plate l9. This plate is provided with a central-opening 22 which is preferably smaller. than the opening I8, I and latex which passes or drips through the opening I8 is therefore caught bythe plate IS. The plate 70 I9 is provided with a second series of accelerator members .or fins 20, similar to,them'embers it of the plate l5, but. extending inwardly to a position closer to the axis'of the rotor than the c entral-openin'g l8 in the plate l5. These'accelerator members or fins perform the same function as the accelerator members or fins l8, and

. accelerate latex insufiiciently accelerated by the fins I6. Latex which is adequately accelerated 5 by the fins 20 may pass outwardly from the cage l0 compartment of the cage may pass downwardly through the opening 22, just as latex insufiiciently accelerated in the uppermost compartment passes downwardly through the opening I8. The

opening 33 in the lowermost section of the main body of the rotor is smaller than the opening 22 in the plate is, and latex which passes or drips through the opening 22 is therefore caught by the upper surface, of this base member of the rotor. This lowermost section is provided with a series of accelerating members or fins 23, which accelerate the latex passing to the lowermost of the three superposed accelerating compartments just as the fins 28 of Ayres Patent 2,138,468 serve to accelerate the entire body of latex in the pre- 5 liminary accelerator orfeed section of the ma- 30 accelerating compartment'as well as in the two upper compartments as illustrated, if desired. The plates l9 and I5 are provided with openings 30 and 3| respectively, affording communication between the three superposed accelerator compartments or zones described above and the acceierating function of this part of the rotor and the function of passing latex outwardly from the accelerator section toward the circumferential wall of the rotor is thus divided between the do three sections discussed above.

! ,Fluid passed outwardly toward the wall of the rotor by the accelerator members It, 20 and 23 respectively is maintained at, or accelerated to, the speed of the rotor by a -p 1u-. d5, rality of accelerator members '24, which, in the embodiment illustrated surround the accelerator cage l3, and extend from this cage into contact with the inner circumference of the main bpdy of the rotor. 'Liquid passing into the space surrounding the accelerator structure described above passes upwardly into contact with a wall 25, which divides the accelerator section l2 of the rotor from the main body 21 of the rotor in which subsidence to eifect the desired concentration and/or separation occurs. I

The main body 21 of the rotor is preferably of I generally similar construction to the main body of the rotor of Ayres Patent 2,138,468, and serves. in a manner well understood by those skilled in 60 thisart, to effect concentration of the latex emulvided for communication with the nozzle II, in

order that an auxiliary flushing or other liquid may be passed to the centrifugal rotor at intervals, if desired.

The operation of the machine of the invention, and the manner in which the advantages of the invention are attained in the use of that machine, will be obvious from the above description. In the concentration of latex, for example, the fluid to be concentrated is jetted upwardly through the nozzle into contact with the spreader or deflector 32. The material so deflected strikes the plate l and is subjected to the accelerating effect of the accelerator members or flns' l6. 0! the latex which is adequately accelerated by the members It, a part passes outwardly through the circumferential wall of the accelerator cage is and a part passes upwardly through the openings H in the top of that accelerator cage. Latex which is inadequately accelerated by the members it passes downwardly through the openings I 8 into contact with plate I9. Latex contacting the plate I8 in this manner undergoes the same action as latex contacting the plate It, and latex which is adequately accelerated by members passes outwardly through the openings 2|, or upwardly through the openings 3|, in either of which cases it is ultimately discharged through the openings I! or 2| from the accelerator assemblage. members 20 passes downwardly into contact with Latex adequately accelerated by the the members 23 and is accelerated by those memdial zone of the rotor between the zones of the most concentrated and most dilute phases formed by subsidence in the section 21 of the rotor. After subsidence in the section 21 to effect movement of rubber particles inwardly and consequent formation of a relatively concentrated latex toward the center of the rotor and a relatively dilute latex toward the circumferential wall of the rotor, these relatively concentrated and relatively dilute phases are discharged respectively through the outlets 28 and 29.

It will be evident from the above description.

that the accelerating function of the members It is supplemented and augmented by the accelerating members 20 and 23. When the accelerator members 16 become partially clogged by coagulation, sedimentation or otherwise, the supplemental accelerator members 20 and 23 continue to perform their accelerating functions, and the necessity for shutting down the machine for cleaning because of such coagulation or sedimentation is thereby very materially postponed. It will be evident from the above discussion that the function of the machine of the Ayres patent in bringing the emulsion up to speed with avoidance of violence is materially improved. It will also be evident that the machine of the present invention prolongs the working cycle as compa ed to the machine of the Ayres patent, and minimizes or prevents loss of latex by discharge from the rotor away from the principal subsidnce section of the rotor.

Modifications of the invention will be obvious to those skilled in the art, and I do not therefore wish to be limited in interpretation of the invention, except by the scope of the subjoined claims.

I claim: 1. In a centrifugal separator, the combination comprising,a centrifugal rotor including a preliminary accelerator section and a subsidence celerator section is adapted to flow from said accelerator section, said accelerator section comprising a transversely extending, centrally periorated accelerator plate, accelerator members on said accelerator plate, a second accelerator plate spaced longitudinally from said first-mentioned accelerator plate and adapted to receive fluid insufficiently accelerated by said first-mentioned accelerator members, said second-mentioned accelerator plate having a central perforation of smaller diameter than the central perforation of said first-mentioned accelerator plate, and further accelerator members on said secondmentioned accelerator plate.

2. In a centrifugal separator, the combination comprising, a centrifugal rotor including a preliminary accelerator section, and a subsidence section longitudinally spaced from said accelerator section into which liquid accelerated in said accelerator section is adapted to flow from said accelerator section, said accelerator section comprising a transversely extending accelerator plate, means to feed liquid into contact with said accelerator plate, accelerator wings extending outwardly on said plate, the space occupied by the outer portion of the said wings communicating with the subsidence section of the rotor, whereby liquid passing to theiouter portion of said plate by reason. of acceleration by said wings is passed to the subsidence section of the rotor, said plate being provided with an opening in its central portion, and accelerator means axially spaced from said accelerator plate positioned to receive and accelerate liquid passed through said opening, the outer portion of said accelerator means also communicating with-the subsidence section of the rotor.

3. In a centrifugal separator. the combination comprising, a centrifugal rotor including a preliminary accelerator section, and a subsidence section longitudinally spaced from said accelerator section into which liquid accelerated in said accelerator section is adapted to flow from said accelerator section, said accelerator section com prising a transversely extending accelerator plate, means to feed liquid into contact with said accelerator plate, accelerator wings extending outwardly on said plate, the space occupied by the-outer portion of the said wings communicating with the subsidence section of the rotor, whereby liquid passing to the outer portion of said plate by reason of acceleration by said wings is passed to the subsidence section of the rotor,

section into which fluid accelerated in said acsaid plate being provided with an opening in its central portion, and accelerator means axially spaced from said accelerator plate and including an accelerator plate and accelerator wings on said plate positioned to receive and accelerate liquid passed through said opening, the outer portion of said accelerator means also communieating with the subsidence section of the rotor.

4. A centrifugal separator as defined in claim 2, in which said accelerator plate and accelerator means are mounted in a cage provided with outlets for discharge of liquid to the subsidence section of the rotor.

5. In a centrifugal separator, the combination comprising a centrifugal rotor mounted for rotation on a vertical axis, and including a preliminary accelerator section, and a subsidence section into which liquid accelerated in said accelerator section longitudinally spaced from saidaccelerator section is adapted to flow from said accelerator section, said accelerator section comprising a transversely extending accelerator plate,

means to feed liquid into contact with said accelerator plate, accelerator wings extending outwardly on said plate, the space occupied by the outer portion of the said wings communicating with the subsidence section of the rotor, whereby liquid passing to the outer portion of said plate by reason of acceleration by said wings is passed to the subsidence section of the rotor, said plate being provided with an opening in its central portion, and accelerator means axially spaced from said accelerator plate and positioned below said opening to receive and accelerate liquidpassed through said opening, the outer portion of said accelerator means also communieating with the subsidence section of the rotor.

6. In a centrifugal separator,.the combination comprising, a centrifugal rotor mounted for rotation on a vertical axis, and including a preliminary accelerator section in the lower portion of said rotor and a longitudinally spaced subsidence section above said accelerator section into which liquid accelerated in said accelerator section is adapted to flow from said accelerator section,

' said accelerator section comprising transversely extending accelerator means, accelerator wings extending outwardly on said accelerator means, means for jetting liquid upwardly centrally through said accelerator section, means for deflecting said liquid fed upwardly to the'rotor in a direction downwardly into accelerating contact with said accelerator means, means for directing into said subsidence section liquid which is sufficiently accelerated by said accelerator means, and a secondary accelerator means spaced longitudinally below said first-mentioned accelerator means and adapted to receive and to accelerate liquid insufflciently accelerated by said firstmentioned accelerator means, the outer portion of said accelerator means also communicating with the subsidence section of the rotor.

7. In a centrifugal separator, the combination comprising, a centrifugal rotor including a preliminary accelerator section, and a subsidence section longitudinally spaced from said accelerator section into which liquid accelerated in said accelerator section is adapted to flow from said accelerator section, said accelerator section comprising a transversely extending accelerator plate, means to feed liquid into contact with said accelerator plate, accelerator wings extending outwardly on said plate, the space occupied by the outer portion of the said wings communicating with the subsidence section of the rotor, whereby liquid passing to the outer portion of said plate by reason of acceleration by said wings is passed to the subsidence section of the rotor,

said plate being provided with an. opening in'its central portion, accelerator means axially spaced from said accelerator plate and positioned to receive and accelerate liquid passed through said opening, and means for directing liquid ac-.

celerated by said accelerator plate and said ac-.

celerator means into a portion of the subsidence section of the rotor lying radially inwardly of the inner circumferential wall of said subsidence section. I

JOHN J. SERREIL, Jli.

CERTIFICATE OF CQRRECTION.

Patent No. 2,259, 665. October 21, 19b1,

\ Joan J. SERREILL, in.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, second column, line 55, claim 2, after .the word "p1ate" insert --'ahd--; Iines 72 and 75, claim 5, strike out the words "longitudinally spaced from said accelerator section" and insert the same before 'into' in line 71, same claim; and that the shid Letters Patent should be read. with this correctio therein that the same may conform to the recorder the case in the Patent Office.

.Signed and' sealed this 16th ciay of December, A. 1). 19m;

2 Henry Van Arsdale, (Seel) ActingComissioner'of Patents; 

